The heart consists of 4 valves that are responsible for the passage of blood to the heart and from the heart to other organs of the body :-
Mitral Valve - Mitral valve, also known as the bicuspid valve is one of the four valves of the heart. It is located between the upper left and lower left chambers of the heart. Also known as the bicuspid valve, the mitral valve is the only valve that has two flaps or cusps instead of three. The valve opens and closes based on the pressure differences in the upper and lower left heart chambers. The leaflet opens when there is greater pressure in the upper left chamber(left atriums) and closes when there is greater pressure on the lower left chamber (left ventricle). All of this happens within the duration of our heartbeat. The upper left chamber of the heart receives blood rich in oxygen from the pulmonary veins situated in the lungs. When the upper left heart chamber is filled with oxygen-rich blood, the mitral valve opens and blood flows to the lower left heart chamber. After transferring the blood to the lower left heart chamber, the mitral valve closes immediately to prevent regurgitation.
Tricuspid Valve - Also known as the right atrioventricular valve, the tricuspid valve is a boundary existing between the upper right heart chamber and the lower right heart chamber. The tricuspid valve is responsible for the transformation of deoxygenated blood into oxygen-rich blood. The blood flows from the upper right heart chamber to the lower right heart chamber and it then exits the heart through the pulmonary artery. The pulmonary artery then transfers blood to the lungs for its oxygenation. The tricuspid valve is named so because it has three flaps or leaflets or cusps that, after receiving blood from the upper right chamber of the heart (right atrium), closes immediately to prevent blood from flowing back to the right atrium, that is, it prevents tricuspid regurgitation. The tricuspid valve is located above the lower right heart chamber, on the right dorsal side of the heart.
Pulmonic Valve - Pulmonic valve, also known as the pulmonary valve is the valve that helps circulate blood in the body. The pulmonary valve is located between the lower right heart chamber and the pulmonary artery. The pulmonary valve opens when the pressure in the lower right heart chamber(right ventricle) rises above the pressure in the pulmonary artery and the valve closes on,y when the pressure in the right ventricle drops rapidly. Regurgitation cannot take place in the pulmonary valve since it is a unidirectional valve, that is, in the case of the pulmonary valve, blood cannot flow back into the heart.
Aortic Valve - The aortic valve is the last valve of the heart, located between the lower left chamber of the heart and the aorta. The aorta is the largest artery in the body. This is one of the most important structures of the circulatory system since it originates from the lower left heart chamber and extends to the abdomen where it transports oxygenated blood to all parts of the body. The aortic valve opens when pressure rises in the lower left heart chamber(left ventricle), allowing the passage of blood to exit from the heart to the aorta where it gets distributed to all the organs of the body. When the pressure in the left ventricle drops the aortic valve closes
Mitral Valve and Tricuspid Valve - located between the upper and lower chambers of the heart (atria and ventricles). During half of the heartbeat, they let blood flow towards the heart and close so that the blood does not flow backward. There is an exchange of blood flow between the right and left upper heart chambers and the right and left lower heart chambers. Blood flows from the upper right heart chamber to the lower right heart chamber through the open tricuspid valve. The Mitral valve helps in the passage of blood flow through the upper left and the lower left heart chambers. The Mitral valve only has two leaflets whereas the rest have three leaflets to push blood flow to the heart. When the lower right heart chamber (right ventricle) is full, the tricuspid valve closes and prevents the blood from flowing backward and vice versa.
Pulmonic Valve and Aortic Valve - located between the lower heart chambers and blood vessels that leave the heart. They are responsible for transporting blood to other organs of the body. They do this when the lower right chamber closes. Blood is pumped out from it through the pulmonic valve that transports it to the lungs through the pulmonary artery. When the lower-left chamber closes, blood is pumped out and transferred to the arteries through the aortic valve. When the lower right heart chamber completes contracting and starts relaxing, the pulmonic valve shuts down which prevents blood from flowing back to the lower right heart chamber. When the lower-left heart chamber stops contracting and starts relaxing, the aortic valve shuts down which prevents blood flow back to the lower-left heart chamber. This process is repeated, causing blood to flow continuously between the heart, lungs, and other organs of the body. Therefore, functional valves prevent any kind of blood leakage from the heart.